Where is this question from? Based on the passage, we have the following information:
* Test scores are higher at Nesbit Public Schools than at Jasper Public Schools. We have no information about test scores at private schools. So, we have some reason to think that Nesbit Public Schools are better than Jasper Public Schools, but no reason at all to think that Nesbit public schools are better than private schools in either Jasper or Nesbit;
* Jasper parents have increasingly *chosen* to spend money to send their children to Jasper private schools. That's evidence that, at least in the opinion of parents in Jasper, private schools there are preferable to public schools there;
* The population of students in Jasper public schools has been changing: Jasper parents are increasingly sending their children to private schools. There is certainly the possibility of sample bias here; perhaps the most promising students are the ones being sent to private schools, and Jasper Public School test scores are lower than those in Nesbit because the remaining students at Jasper public schools are worse, and not because the education in Jasper is worse;
* With the decrease in students in Jasper public schools, there is the possibility that the student-teacher ratio there is substantially better than elsewhere. The stem suggests (though does not state outright) that this is one factor determining the quality of education.
There just is not enough information to give a good answer here; you can, depending on how you look at the stem, provide a justification for many different education choices for the hypothetical student in the question. Indeed, the equivalence that the OE uses to justify answer E (higher test scores = better education) is precisely the type of overly simplistic conclusion that GMAT CR questions are often asking you to identify and weaken. I really don't like this question.